Document jreleaser/jreleaser#1952

Author: aalmiray

docs/modules/extensions/pages/authoring-extensions.adoc

@@ -151,6 +151,7 @@ Create a Java file with the following structure:
 ----
 //DEPS org.jreleaser:jreleaser-model-api:{jreleaser-version}
 //DEPS org.kordamp.jipsy:jipsy-annotations:1.2.0
+//DEPS org.kordamp.jipsy:jipsy-processor:1.2.0
 
 package com.acme;